private Task <FileOperationContext> EncryptionUpgradeWorkAsync(IDataStore store, IProgressContext progress)
{
FileOperationsController operationsController = new FileOperationsController(progress);
operationsController.QueryDecryptionPassphrase = HandleQueryDecryptionPassphraseEventAsync;
operationsController.KnownKeyAdded = new AsyncDelegateAction <FileOperationEventArgs>(async(FileOperationEventArgs e) =>
{
await _knownIdentities.AddAsync(e.LogOnIdentity);
});
return(operationsController.EncryptionUpgradeAsync(store));
}